1. Field of the Invention
The present invention relates to a method for fabricating a plasma display panel and particularly, to a method for fabricating a plasma display panel, capable of improving contrast of the panel by preventing a fluorescent layer from being formed in an upper portion of a partition.
2. Description of the Background Art
FIG. 1 is a cross-sectional view showing a general plasma display panel. As shown in the drawing, the plasma display panel includes an upper substrate 101 for displaying an image, a sustain electrode 102 which is abutted on the lower portion of the upper substrate 101, and is at right angles to an address electrode which will be described hereinafter in a cell region of the panel, a bus electrode 103 which is positioned at a portion of the lower portion of the sustain electrode 102, a dielectric film 112 which is positioned on the lower front surface of the upper substrate 101, a protection film 111 which is formed in the lower portion of the dielectric film 112 and is abutted on a partition which will be described hereinafter, for protecting the dielectric film 112, a lower substrate 106 which is combined in parallel with the upper substrate 101 in a positioned separated in the lower direction of the upper substrate 101, a bottom plate film 107 which is positioned in the upper portion of the lower substrate, 106 for reflecting visible light, the address electrode 105 which is positioned in the upper portion of the bottom plate film 107, for generating discharging with the sustain electrode 102 in the cell region, a dielectric film 108 which is positioned on the upper front surface of the address electrode 105 and bottom plate film 107, the partition 109 which is positioned in the upper portion of the partition 109, for dividing the cell region, a black matrix which is positioned in the upper portion of the partition 109, and a fluorescent layer 104 which is formed on the side surface of the partition 109 and in the upper portion of the dielectric film 108 in a predetermined thickness, for generating respective R, G and B visible rays by ultraviolet rays.
Hereinafter, the conventional method for fabricating the plasma display panel with the above composition will be described as follows.
Firstly, the bottom plate film 107 for reflecting visible rays is formed in the upper portion of the lower substrate 106 which is a glass substrate. The address electrode 105 which is transparent and lengthened in a predetermined direction that Indium Tin Oxide (ITO) is coated and patterned is formed in the upper portion of the bottom plate film 107, the dielectric film 108 is deposited on the upper front surface of the address electrode 105 and bottom plate film 107, and the partition 109 for defining the cell region in the upper portion of the dielectric film 108 is formed. Also, a black matrix is formed in the upper portion of the partition 109, and the fluorescent layer 104 is printed inside the cell region which is defined with the partition 109, black matrix and dielectric film 108 using the screen printing method. At this time, to form a fluorescent layer 104 by the screen printing method, fluorescent paste is printed several times to completely fill the paste inside the cell region and is dried at temperature of 120xcx9c150xc2x0 C. The above process is repeated in the cell regions corresponding to the colors about the R, G and B colors. Through the process, preparation of the lower plate is completed by forming a fluorescent layer 104 respectively corresponding to R, G and B in the cell regions and then calcining it at temperature of 350xcx9c450xc2x0 C.
Also, the sustain electrode 102 and bus electrode 103 are formed at the lower portion of the upper substrate 101, the dielectric film 112 is formed in the lower portion of the sustain electrode 102 and bus electrode 103, and then a protection film 111 for protecting the dielectric film 112 is formed in the lower portion of the dielectric film 112. Generally, the protection film 111 is a film composed of MgO, and preparation of the upper plate is completed by forming the protection film 111.
Then, discharging gas is injected in the cell region through an injection port after combining the upper and lower plates so that the injection port is formed between the upper and lower plates. At this time, the injected discharging gas is composed of He, Ne and Xe. As described above, the fluorescent layer 104 is excited by ultraviolet rays generated in the discharging gas, and the visible ray of colors displayed by the fluorescent layer 104 is displayed on the panel.
However, the method for forming a fluorescent layer using the screen printing method had an advantage that the equipments of the process could be purchased at low costs, but contrast of the panel was decreased since the fluorescent layer could be easily formed in the upper portion of the partition 109 or in the upper portion of the black matrix.
Therefore, an object of the present invention is to provide a method for fabricating a plasma display panel, capable of improving contrast of a panel by forming a fluorescent layer using an inkjet printing method.
Also, the present invention is to provide a method for fabricating a plasma display panel, capable of improving contrast of the panel by charging a liquid flake of fluorescent ink with electricity to have a predetermined polarity, applying a voltage having a polarity opposite to the charged state to an address electrode, and preventing the fluorescent material from being printed on the upper portion of the partition.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a method for fabricating a plasma display panel, including the steps of sequentially forming a bottom plate film and an address electrode on an upper portion of a lower substrate, forming a dielectric film in the upper portion of the bottom plate film and address electrode, defining a cell region by forming a partition in the upper portion of the dielectric film and forming a fluorescent layer using an inkjet printing method in the cell region.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.